Conventionally, an oral administration method using a tablet, a capsule, a syrup or the like has been known as a method for administering pharmaceutical. However, in recent years, an approach has been tried in which drugs are transdermally administrated using a patch. The administration method using a patch can overcome problems associated with the oral administration method and, in addition, has advantages such as a decrease in the administration frequency, improvement of compliance, ease of administration as well as ease of discontinuation thereof. Therefore, use of a patch is considered promising as a useful administration method for a drug, especially in a case where patients are elderly or children.
However, the stratum corneum of the normal skin has a barrier function for inhibiting exogenous materials from penetrating into the body. Due to the barrier function, compounded medicinal ingredients are often not transdermally absorbed sufficiently when conventional patches are used. Further, since the stratum corneum has a high lipid solubility, the skin permeability of a drug is generally extremely low.
Therefore, in order to enhance the transdermal absorption properties of a drug in the transdermal administration method, studies are being carried out concerning the composition of an adhesive agent for use in a patch and the like. As one part of such studies, a patch has been proposed that uses polymer material such as acrylic polymer or rubber polymer as an adhesive base agent (JP-A-4-266821, JP-A-9-301854 and the like).